1. Field of the Invention
The present invention relates generally to filters and, more particularly, to a disposable filter for removing particulate matter from an aqueous flow, especially radioactive materials entrained in cooling water, which provides an improved cartridge-style filter for use in such installations to reduce the volume and weight of the hazardous waste resulting from the end of life of the filter.
2. Description of the Prior Art
Nuclear reactors use circulating water as a coolant for the radioactive core. Some of the particles picked up by the cooling water are radioactive. Before the water can be recirculated in the cooling loop, the radioactive materials must be removed. This is done conventionally by filter elements that are installed for a given period of time to remove the waste particles. After a period of time, the filter becomes clogged with removed particles and must be replaced.
Conventional filters for this purpose have a perforated, cylindrical stainless steel outer hull or, in some cases, an inner core, and a permanently installed interior filter medium. The filtrate flows from inside to outside through the filter medium and the pores of the stainless steel. The stainless steel hull has been considered a necessity to give the filter the structural strength and integrity to withstand the temperature, pressure and dynamic filtration loads of the forces of the flowing coolant and avoid corrosion.
However, when the filter is spent, the hull or core becomes a large, strong, corrosion resistant, heavy piece of hazardous, radioactive waste. Requirements for disposal of this type of waste safely are very costly. The steel is difficult to compress to a reduced volume and does not easily shred to smaller pieces. Disposal of the filter, therefore, requires a great deal of cost.
Thus, there remains a need for a new and improved disposable filter which performs well in existing facilities while, at the same time, reduces the cost of disposal of spent filters contaminated with hazardous materials such as radioactive particulate matter.